YBOR CITY — The county bus system accelerated to the front of the pack Thursday, becoming the first public transit system in the state to begin conversion from diesel to natural gas.

By making the switch, the Hillsborough Area Regional Transit Authority, or HART, will save $2.5 million in fuel costs over the next nine years. The switch will also cut greenhouse gas emissions from its buses and vans by 252 tons per year — as much carbon dioxide as 1,128 passenger vehicles emit, said HART Chief Financial Officer Jeff Seward.

The conversion helps cut dependence on diesel, much of which is imported, and will help boost development of natural gas in the United States, said HART Chairman Mike Suarez. “That’s a huge savings to taxpayers and a huge benefit to those that breathe the air.”

The switch begins in the coming weeks as the agency deploys 28 new compressed natural gas vans to replace its diesel-powered HARTFlex vans for on-demand curbside service and HARTPlus vehicles for people with disabilities. The transit authority plans to put 22 new natural gas-fueled buses on the road early next year.

HART upgraded its fleet using a portion of two federal grants.

“It saves us money and steers us toward being a more environmentally sustainable agency,” Seward said, during the ribbon-cutting ceremony for the new fuel station at HART’s maintenance yard and bus garage on 19th Avenue.

Patrick Sheehan, director of the state’s Office of Energy, said the HART conversion is “the beginning of what Florida has the opportunity to experience across the state.” Two-thirds of the $70 billion Florida spends on energy each year is petroleum-based, he said. “Natural gas gives us the opportunity to cut in to that trade deficit using home-produced natural gas. We won’t have to exclusively use petroleum to get to work, school and church.”

Three years ago, Sheehan said, Florida had 30 natural gas fuel stations. Today, it has almost triple that number and growing. The use of more natural gas to fuel fleet and passenger vehicles, he said, will lead to a cleaner Florida environment. “We want to make sure every county has access to cheap natural gas.” The switch, he said, is helping to fuel “a tremendous resurgence” in Florida’s economy.

Last year, HART experienced its most robust ridership, ever, hitting 1.4 million riders in October 2013. Agency officials are working on new and more convenient routes that would increase ridership even more. A good portion of that energy is going in to the South Shore area where new subdivisions, big-box stores, a hospital and a mall are all going in.

Transit is of huge importance in Florida’s future, said Florida Department of Transportation Secretary Ananth Prasad. “No one solution fits every area, but we want to grow transit at twice the rate of the population growth.”

During the next five years, Prasad said, a system of express lanes will be constructed on area highways that will include space for buses. The concept is already in practice and very successful in Broward and Miami-Dade counties, he said.

Prior to Thursday’s ground breaking, TECO Peoples Gas laid three miles of natural gas pipeline to the HART maintenance yard and will provide the fuel for the vehicles. Clean Energy Fuels Corp., based in California, built and will operate the fueling station.